Meter measures Dissolved Oxygen (DO) to determine water quality in a variety of applications including wastewater, aquariums and fish hatcheries. Simultaneously displays DO and temperature readings. Unit holds and recalls minimum and maximum readings. Features automatic temperature compensation and calibration to air. Meter is ready for use and includes a soft carrying case with belt loop, two spare probe heads, electrolyte and 4 AAA batteries. Replacement electrolyte sold separately.